Enclosed switch



April 278, 953 R. N. RowE 2,636,960

ENCLOSED SWITCH Filed March 15, 1950 2 SHEETS-SHEET l IIN" ' INVENTOR.P41/AMA@ /14 {0h/f Patented Apr. 28, 1953 ENCLOSED SWITCH Raymond N.Rowe, Plainville, Conn., assignor, by

mesne assignments, to General Electric Company, a corporation of NewYork Application March 15, 1950, Serial No. 149,849

('Cl. 20G-133) 3 Claims. 1

Modern electric apparatus especially enclosed switches employ cartridgetype fuses. Sometimes these fuses have flat blade terminals andsometimes cap terminals. In any case, the fuses are removably supportedby clips or clamps of various types.

When current is iiowing through a switch, the fuses, being thermallyfunctioning devices, generate heat, and since this heat has no readymeans of escape, the fuses and adjacent terminals bec-ome very hot, andin time heat up the air in the switch enclosure, cause oxidation andannealing of various parts and increase of contact resistance at thefuse holders.

It is the main object of my invention to provide practical meansapplicable to various types of enclosed devices for preventing theoverheating of the fuses and clamps and consequent damage.

It is another object to protect enclosed switches.

It is another object to protect enclosed devices having multiple fuses.

I have accordingly provided means for conducting heat from the fuseholders and radiating it outside the switch receptacle. For thispurpose, I provide metallic rods or tubes thermally connecting the fuseholders but electrically insulating the rods or tubes which rods ortubes are connected to the opposite side walls of the receptacle andpreferably to radiating ns or plates outside of the receptacle.

The accompanying two sheets of drawings show the preferred embodiment ofthe invention and one modification.

Fig. l is a front view of an enclosed switch embodying one form of myinvention, the cover being broken away to show the interior.

Fig. 2 is a plan view of the form of Fig. 1, parts of the receptaclebeing broken away.

Fig. 3 is a side view of the radiating plates of Figs. 1 and 2.

Fig. 4 is a horizontal section showing a fragment of the thermalradiating members of Figs. 1 to 3 taken on the plane of the line 4-II ofFig. 2.

Fig. 5 is a fragmentary sectional view taken on the plane of the line5-5 of Fig. 2.

Fig. 6 is a front view showing a radiating rod with fuse terminalconnections.

Fig. 7 is a side view showing one form of switch unit with fuse clampsand radiating rods.

Fig. 8 is a fragmentary horizontal section showing another form ofradiating members.

The body I of the receptacle and the cover 2 are usually of metal, andenclose switch snap action and switch contact mechanism and fuses. Inthe form shown, the base 3 carries snap action mechanism of any suitabletype. My Patents 2,468,463 and 2,475,338 and 2,494,314 may be referredto as suitable but not as limiting the invention herein claimed to suchforms. The base is supported on flanges 4 at opposite sides of thereceptacle and secured by screws 5. An actuating shaft 6 extends throughthe cover and is provided with a suitable handle (not shown).

The switching device 'I may be of any suitable type such for instance asthat shown in my Patents 2,468,235 or 2,494,315 but the presentinvention is not limited to any special form. The movable switch member8 is actuated by the crank shaft 9 from the snap action mechanism inbase 3. The cross bar I0 extends across the receptacle and serves toactuate the various switch units, in this instance, three.

Each switch unit 'I has circuit terminals II and I 2 of any suitableform and is provided with a circuit protection fuse I 4 of any suitableform. In Figs. 1 and 2 and 5 the fuse has conventional cylindrical capsor ferrules and is removably mounted in spring clips I5, I5 ofconventional form.

A fuse clamp I5 of Fig. 5 is mounted on each of a pair of spaced fuseterminals I6 on each switch unit by means of the extension I 'I andscrew I8. A metal rod I9 is connected to a fuse clip of each of thetransversely situated switch units 'l by means of metallic 'straps 20,the ends of each ofveach of which are secured by a screw I8. Each strapencircles the rod I9 but is electrically insulated from its clamp by aninsulating sleeve 2l which may be applied in any suitable manner. Thisstrap may be perforated at 22.

A rod I 9 extends across the outer side of the upper row of the fuseclamps and a bar I9 extends across the lower row of the fuse clamps, thefuses extending between the respective pairs of fuse clamps beingsubstantially parallel as shown.

Each end of each rod is secured to a side wall of the receptacle by ascrew 23 so as to radiate heat conducted from the transverse rods.

I also prefer to provide radiating metal plates 24 and 25 secured to therods by screws 23, and 23 but spaced from the wall l by washers 26 and26 so as to permit air to circulate around the plates.

In Fig. 6, I have shown a modication in which the various fuse terminalsare insulated individually from the radiating cross members byinsulating sleeves 3B which are inserted between the terminal straps 20'and the member I9. A

a layer of metal foil 3l may be interposed between each strap and sleeveto increase local thermal conductivity.

In Figs. 6 and '7, the fuse I4' has terminal blades mounted in fuseclamps l5' such as set forth in my Patent 2,453,019. The form of clamphowever is immaterial to the present invention. The endofastrap .28.issecured `between the `fuse terminal I6 and.clamp."|5. 'l

In Fig. 8, I have shown a tubular radiating cross member lS which ismounted in the recepr tacle by means of a screw threaded sleeveZBY.These sleeves may also support radiating 'plates 24x. These tubularradiating Amembersprovide increased radiatingsurfacesrand'lirlmt.circulation of air through the tubes.

From the foregoing, it will be seen that the cross rods or tubesconstitute` thermallylndcltive heat radiating extensions from thevariousfuse terminals and that they conduct heat to the anfar angement isespeciallyyalluable for 12mg haunggefrectj 'Q'f the enclosed-ft-v36311111einentsHieke` it nesafy ,enclos'e'the vruses that'direct'.radiation: from 'sible.""

theformishown, theA crossrods kor ,tubes not electrically cbnnlatithereto .and Supporting Aone. @ad-ef la fuse'. extending 'betweenfee-111 reir Qfrs-aid-Qlipsrsaid Contact Clins-abelis-Iiesd.Sunmaimerasf t,- @Xtendin @We IQWS' -ClQSS Asaid receptacle, twoheatconducting rodsv inf'said enclosure extending across said enclosurerespectively. adjacentsaid rows of Contact clips, aplu- ,rality of ,heatconducting members secured to each .of lsaid .rods in electrically`insulating heat conducting Arelation vwith said ,rods and secured.,eachito one of said contact clips in heatconcluctying' relationtherewith, .and meaiisfor securing opposite Walls of .said enclosure.against the ,ends loflsaidflrods so.' as toformfa heat vconducting .re-

2T The combination `in an .enclosed switch, metalA walls forming anenclosure, fa plurality of .switching devices mounted infsaid enclosure,a

pair offfuseitrminalslneach of said'v switching devices, aconta'ct clipsecured to Teach of said terminals -for.electrically',connecting theretoand supporting one .end of a fuse extendingbetween each pair of saidclips, said contact clips being positioned in such manner as to extendin two rows across said receptacle, two heat conducting rods in saidenclosure extending across said enclosure respectively adjacent saidrows of contact clips, a plurality of heat conducting members secured toeach of said rods in electrically insulat- .ingheatconducting relationwithlsaidnrods and se'curedxeach toone of said contact, clips in heatconducting relation therewith, a heat radiating alnsttheoiiterfsurfaceof its said wall and the heatradiating member.

' 3. The lcombination in an enclosed switch,

elect-fiala. conceding thereto.aadfsuprrtone end oa fils@ @Xiediee:between each pair fof'said clips, said contact-clips being positionedlin ai@ 'meneer that, said fuse a 11.1.1 'substantial parallelrelationYwitheachother and Lsalidcl' ,maand poripns irl. enseeinentwith, eachother Y Ithriasfsad said. @radiales rs

